[mythtv-users] OT (?) heat/noise: underclocking vs. cpufreq
atd7 at cornell.edu
Fri Feb 27 17:28:00 EST 2004
Quoting Franco <net.surfer at tiscalinet.it>:
> I hope this isn't too OT; however I recall
> somebody recently wrote that the heat/noise issue
> is interesting for most mythtv users.
> I found http://www.silentpcreview.com/ an excellent source
> of information on this regard. Among the other things, they
> have a (partial) list of motherboards that easily allow
> undervolting/underclocking (click on recommended ->
> undervoltable motherboards).
> Before I make my purchase based on this partial list,
> do you know about other undervoltable/underclockable
> motherboards, that are not in that list but are maybe
> more suitable for a mythtv box?
> I also have another big question: ;-)
> did anybody try to play with the "cpufreq" module?
> Does it work? It would be very nice to be able to
> change the CPU frequency on the fly... one could
> make a powerful/hot/noisy box for normal usage,
> and then make it slow/cool/silent when he wants to
> listen music...
> One could also fine-tune the best tradeoff between
> speed and noise, without having to buy a dozen
> different processors for trial and error... ;-)
CPUFreq patches for 2.4 - Pain in the arse to get one that works with any recent
kernel. The last one I got to work was 2.4.18 (Maintenance of the 2.4 cpufreq
patches is... lacking.)
CPUFreq in kernel 2.6 works very well if you have a supported CPU/chipset. I
believe the p4-clockmod module works with any P4 processor and only scales
frequency but not voltage, but I'm not sure. The Speedstep variants only work
with mobile chipset/CPU combos. (speedstep-ich and p4-clockmod both work well
on my Dell Inspiron 8200)
I'm hoping that eventually p4-clockmod capability is added to the speedstep-ich
module, as both CPU scaling methods CAN be used together, unfortunately to do it
with CPUFreq requires loading/unloading modules currently.
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